Tumour budding in pancreatic cancer revisited: validation of the ITBCC scoring system

Tumor Budding Is an Independent Adverse Prognostic Factor of Pancreatic Ductal Adenocarcinoma Patients Treated by Resection After Preoperative Chemoradiotherapy

OBJECTIVES

To examine the significance of tumor budding as a prognostic factor of resected pancreatic ductal adenocarcinoma (PDAC) specimens after preoperative chemoradiotherapy (CRT).

MATERIALS AND METHODS

Among 162 PDAC patients who underwent pancreatectomy after gemcitabine and S1-based CRT from 2012 to 2019, 131 were evaluated for tumor budding. Tumor buds were counted at the invasive front, where the degree of budding was the greatest (hematoxylin and eosin staining, ×20 magnification). Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were compared between the patients without tumor budding (non-TB group) and those with tumor buddings (TB group). Multivariate Cox proportional hazards analysis was conducted to examine the significance of tumor budding as a prognostic factor.

RESULTS

OS, DSS, and RFS (median survival time) of the non-TB group were significantly longer than those of the TB group (OS: 50.7 vs 27.5 months, P  = 0.014; DSS: 63.3 vs 33.0 months, P  = 0.014; RFS: 20.3 vs 11.3 months, P  = 0.028). Multivariate analysis identified adjuvant chemotherapy ( P  = 0.003) as a favorable prognostic factor of OS and tumor budding ( P  = 0.023) as an adverse prognostic factor of DSS.

CONCLUSIONS

This study revealed that the presence of tumor budding was an independent adverse prognostic factor in PDAC patients resected after gemcitabine and S1-based CRT.

Tumor Budding, Poorly Differentiated Clusters, and Stroma Percentage in Uterine Endometrioid Carcinomas Are Morphologic Findings Associated With Adverse Clinical Outcomes

Uterine endometrioid carcinoma (UEC) has well-defined morphologic features that carry prognostic significance and guide treatment. In addition to the well-known features, tumor budding (TB), poorly differentiated clusters (PDCs), and amount of stroma within the invasive front are associated with a poor prognostic outcome in many carcinomas. Here, we evaluate TB, PDCs, and the stroma percentage in UEC and correlate these findings with morphologic features known to be associated with a poor clinical outcome and with recurrence-free survival (RFS). We performed a retrospective search of our institution's EMR for cases of hysterectomy for UEC. We collected clinical data including disease recurrence, death, and data associated with poor patient outcomes. Cases were evaluated for TB, PDCs, and percent stroma by 2 pathologists. Ten 20× fields were examined, and the one with the most PDCs and TB was evaluated. Percent stroma was evaluated in a ×10 field of tumor at the area of deepest invasion. Less than 10% stroma was defined as stroma poor, and >10% stroma was defined as stroma rich. Statistical testing and analysis were conducted, and P-value was set at 0.05. One hundred thirteen cases were evaluated. Decreased RFS was seen with TB (P=0.03), at least 5 PDCs (P=0.01), and stroma-rich tumors (P=0.043). This study shows a statistically significant association between TB presence, at least 5 PDCs, stroma-rich tumors, and decreased RFS in UEC. We conclude that TB, PDCs and stromal evaluation are strong independent prognostic indicators in UEC and provide additional value to the currently used morphologic assessment of UEC.

Multicenter Study on Tumor Budding in Lung Squamous Cell Carcinoma: Comparison Between Biopsy and Resection With Interobserver Variability Assessment

Grading lung squamous cell carcinoma (LUSC) is controversial and not universally accepted. The histomorphologic feature of tumor budding (TB) is an established independent prognostic factor in colorectal cancer, and its importance is growing in other solid cancers, making it a candidate for inclusion in tumor grading schemes. We aimed to compare TB between preoperative biopsies and resection specimens in pulmonary squamous cell carcinoma and assess interobserver variability. A retrospective cohort of 249 consecutive patients primarily resected with LUSC in Bern (2000-2013, n = 136) and Lausanne (2005-2020, n = 113) with available preoperative biopsies was analyzed for TB and additional histomorphologic parameters, such as spread through airspaces and desmoplasia, by 2 expert pathologists (M.M., C.N.). Results were correlated with clinicopathologic parameters and survival. In resection specimens, peritumoral budding (PTB) score was low (0-4 buds/0.785 mm2) in 47.6%, intermediate (5-9 buds/0.785 mm2) in 27.4%, and high (≥10 buds/0.785 mm2) in 25% of cases (median bud count, 5; IQR, 0-26). Both the absolute number of buds and TB score were similar when comparing tumor edge and intratumoral zone (P = .192) but significantly different from the score obtained in the biopsy (P < .001). Interobserver variability was moderate, regardless of score location (Cohen kappa, 0.59). The discrepant cases were reassessed, and consensus was reached in all cases with identification of causes of discordance. TB score was significantly associated with stage (P = .002), presence of lymph node (P = .033), and distant metastases (P = .020), without significant correlation with overall survival, tumor size, or pleural invasion. Desmoplasia was significantly associated with higher PTB (P < .001). Spread through airspaces was present in 34% and associated with lower PTB (P < .001). To conclude, despite confirming TB as a reproducible factor in LUSC, we disclose areas of scoring ambiguity. Preoperative biopsy evaluation was insufficient in establishing the final TB score of the resected tumor.

Spatial Heterogeneity of Immune Regulators Drives Dynamic Changes in Local Immune Responses, Affecting Disease Outcomes in Pancreatic Cancer

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is considered a low-immunogenic (LI) tumor with a "cold" tumor microenvironment and is mostly unresponsive to immune checkpoint blockade therapies. In this study, we decipher the impact of intratumoral heterogeneity of immune determinants on antitumor responses.

EXPERIMENTAL DESIGN

We performed spatial proteomic and transcriptomic analyses and multiplex immunofluorescence on multiple tumor regions, including tumor center (TC) and invasive front (IF), from 220 patients with PDAC, classified according to their transcriptomic immune signaling into high-immunogenic PDAC (HI-PDAC, n = 54) and LI PDAC (LI-PDAC, n = 166). Spatial compartments (tumor: pancytokeratin+/CD45- and leukocytes: pancytokeratin-/CD45+) were defined by fluorescence imaging.

RESULTS

HI-PDAC exhibited higher densities of cytotoxic T lymphocytes with upregulation of T-cell priming-associated immune determinants, including CD40, ITGAM, glucocorticoid-induced TNF-related receptor, CXCL10, granzyme B, IFNG, and HLA-DR, which were significantly more prominent at the IF than at the TC. In contrast, LI-PDAC exhibited immune-evasive tumor microenvironments with downregulation of immune determinants and a negative gradient from TC to IF. Patients with HI-PDAC had significantly better outcomes but showed more frequently exhausted immune phenotypes.

CONCLUSIONS

Our results indicate strategic differences in the regulation of immune determinants, leading to different levels of effectiveness of antitumor responses between HI and LI tumors and dynamic spatial changes, which affect the evolution of immune evasion and patient outcomes. This finding supports the coevolution of tumor and immune cells and may help define therapeutic vulnerabilities to improve antitumor immunity and harness the responsiveness to immune checkpoint inhibitors in patients with PDAC.

The Concept of Stroma AReactive Invasion Front Areas (SARIFA) as a new prognostic biomarker for lipid-driven cancers holds true in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a 'difficult-to-treat' entity. To forecast its prognosis, we introduced a new biomarker, SARIFA (stroma areactive invasion front areas), which are areas at the tumour invasion front lacking desmoplastic stroma reaction upon malignant invasion in the surrounding tissue, leading to direct contact between tumour cells and adipocytes. SARIFA showed its significance in gastric and colorectal carcinoma, revealing lipid metabolism alternations that promote tumour progression.

METHODS

We reviewed the SARIFA status of 166 PDAC cases on all available H&E-stained tumour slides from archival Whipple-resection specimens. SARIFA positivity was defined as SARIFA detection in at least 66% of the available slides. To investigate alterations in tumour metabolism and microenvironment, we performed immunohistochemical staining for FABP4, CD36 and CD68. To verify and quantify a supposed delipidation of adipocytes, adipose tissue was digitally morphometrised.

RESULTS

In total, 53 cases (32%) were classified as SARIFA positive and 113 (68%) as SARIFA negative. Patients with SARIFA-positive PDAC showed a significantly worse overall survival compared with SARIFA-negative cases (median overall survival: 11.0 months vs. 22.0 months, HR: 1.570 (1.082-2.278), 95% CI, p = 0.018), which was independent from other prognostic markers (p = 0.014). At the invasion front of SARIFA-positive PDAC, we observed significantly higher expression of FABP4 (p < 0.0001) and higher concentrations of CD68+ macrophages (p = 0.031) related to a higher risk of tumour progression. CD36 staining showed no significant expression differences. The adipocyte areas at the invasion front were significantly smaller, with mean values of 4021 ± 1058 µm2 and 1812 ± 1008 µm2 for the SARIFA-negative and -positive cases, respectively (p < 0.001).

CONCLUSIONS

SARIFA is a promising prognostic biomarker for PDAC. Its assessment is characterised by simplicity and low effort. The mechanisms behind SARIFA suggest a tumour-promoting increased lipid metabolism and altered immune background, both showing new therapeutic avenues.

Prognostic significance of tumour budding in noncolorectal gastrointestinal tract and pancreatobiliary tract: a systematic review and meta-analysis

Tumour budding shows promise as a prognostic factor in various cancers, but its widespread application is hindered by the lack of large, validated studies and standardized criteria. This meta-analysis aims to review and examine the prognostic role of tumour budding specifically in noncolorectal gastrointestinal and pancreatobiliary tract cancers, broadening our perspective on its clinical relevance. The literature review was conducted through PubMed, Embase, and Web of Science from inception till 20 February 2023. Pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were calculated to assess the relation between tumour budding and clinicopathologic features, as well as overall survival. Each study was evaluated using the Newcastle-Ottawa Scale and both heterogeneity and publication bias were analysed. In this meta-analysis of 57 studies across various cancer types, multivariate HR revealed worse overall survival in oesophageal squamous cell carcinoma (HR 3.34 [95% CI 2.21-5.04]), gastric adenocarcinoma (2.03 [1.38-2.99]), pancreatic ductal adenocarcinoma (2.56 [2.02-3.25]), and biliary tract adenocarcinoma (3.11 [2.46-3.93]) with high-grade tumour budding. Additionally, high-grade tumour budding consistently correlated with adverse clinicopathological features, including lymph node metastasis, lymphovascular invasion, and distant metastasis without any observed inverse association. High heterogeneity was noted. Our study suggests that tumour budding is a valuable prognostic marker in various cancers. Nonetheless, standardized criteria tailored to specific organ types are necessary to enhance its clinical utility.

Network dynamics and therapeutic aspects of mRNA and protein markers with the recurrence sites of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease that typically manifests late patient presentation and poor outcomes. Furthermore, PDAC recurrence is a common challenge. Distinct patterns of PDAC recurrence have been associated with differential activation of immune pathway-related genes and specific inflammatory responses in their tumour microenvironment. However, the molecular associations between and within cellular components that underpin PDAC recurrence require further development, especially from a multi-omics integration perspective. In this study, we identified stable molecular associations across multiple PDAC recurrences and utilised integrative analytics to identify stable and novel associations via simultaneous feature selection. Spatial transcriptome and proteome datasets were used to perform univariate analysis, Spearman partial correlation analysis, and univariate analyses by Machine Learning methods, including regularised canonical correlation analysis and sparse partial least squares. Furthermore, networks were constructed for reported and new stable associations. Our findings revealed gene and protein associations across multiple PDAC recurrence groups, which can provide a better understanding of the multi-layer disease mechanisms that contribute to PDAC recurrence. These findings may help to provide novel association targets for clinical studies for constructing precision medicine and personalised surveillance tools for patients with PDAC recurrence.

Prognostic significance of tumor budding in patients with pancreatic invasive ductal carcinoma who received neoadjuvant therapy

Neoadjuvant therapy is commonly used for invasive pancreatic ductal carcinoma (PDAC). Tumor budding and high podoplanin expression in cancer-associated fibroblasts (CAFs) are prognostic factors in patients with various carcinomas including PDAC who have not received neoadjuvant therapy. In this study, we investigated whether tumor budding and podoplanin-positive CAFs are associated with outcomes in Japanese PDAC patients with neoadjuvant therapy. Histopathological findings of surgically resected PDACs with neoadjuvant therapy from 2005 to 2018 were reviewed (n = 97). With reference to International Tumor Budding Consensus Conference recommendations, tumors were evaluated for budding at 20 × magnification (/0.785 mm2) and at 40 × magnification (/0.237 mm2; mean number of fields: 3) for podoplanin expression in CAFs (%). Overall survival, disease-free survival, and disease-specific survival (DSS) were analyzed using the log-rank test and Cox proportional hazards model. After adjusting for T category, N category, resection margin, and adjuvant therapy, multivariate analyses demonstrated that tumor budding at 40 × magnification was an independent prognostic factor for worse DSS (hazard ratio: 2.41, p = 0.022). Tumor budding at 20 × magnification and podoplanin-positive CAFs tended to be associated with worse DSS; however, these findings were not statistically significant. Our findings indicate that tumor budding is an independent prognostic factor in PDAC patients with neoadjuvant therapy.

Tumor budding as a predictor of disease-free survival in patients with cholangiocarcinoma

Background: Tumor budding is considered a prognostic factor in several solid cancer types. However, we lack comprehensive information on the importance of tumor budding in cholangiocarcinoma. Therefore, we aimed to assess the prognostic value of tumor budding in intrahepatic and extrahepatic cholangiocarcinomas and to evaluate its correlations with other clinicopathological parameters. Methods: We monitored 219 patients who underwent surgery for intrahepatic or extrahepatic cholangiocarcinoma at the Pusan National University Hospital between 2012 and 2021. Tumor budding was evaluated using the International Tumor Budding Consensus Conference scoring system. Tumor budding was classified into low (0-4), intermediate (5-9), and high (≥10). For statistical analysis, tumor budding was divided into two groups based on the cut-off value of 10 (lower: 0-9 vs. higher: ≥10). The correlations between clinicopathological parameters were examined using the chi-square and Fisher's exact test. The prognostic values of the variables were analyzed using the log-rank test and Cox regression analysis. Results: Low, intermediate, and high tumor buddings were identified in 135 (61.6%), 63 (28.8), and 21 (9.6%), patients, respectively. Higher tumor budding was related to the presence of lymphatic invasion (p = 0.017), higher tumor grade (p = 0.001), higher N category (p = 0.034). In the univariable and multivariable analyses, higher tumor budding was associated with shorter disease-free survival in 97 (44.3%) patients who underwent R0 resection (p < 0.001 and p = 0.011). Tumor budding did not significantly correlate with disease-specific survival in entire patients. Conclusion: Tumor budding may serve as a prognostic factor for intrahepatic and extrahepatic cholangiocarcinomas treated with R0 resection.

Tumor Budding as a Marker for Poor Prognosis and Epithelial-Mesenchymal Transition in Lung Cancer: A Systematic Review and Meta-Analysis

Introduction

Currently, tumor budding (TB) is considered to predict the prognosis of patients. The prognostic significance of TB has also been explored in patients with lung cancer, but has not been fully clarified. In the present meta-analysis, we evaluated the prognostic significance, clinicopathological value, and relationship with epithelial–mesenchymal transition (EMT) of TB in lung cancer.

Methods

The MEDLINE, EMBASE, and Cochrane databases were searched up to July 7, 2021, for the relevant articles that showed the relationship between TB and prognosis in patients with lung cancer. For statistical analysis, we used pooled hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs) to assess the correlation between high-grade TB expression and overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), clinicopathological factors, and EMT markers.

Results

A total of 3,784 patients from 10 independent studies were included in the statistical analysis. Our results indicated that high-grade TB was significantly associated with poor OS [HR 1.64 (95% CI, 1.43–1.87)] and DFS [HR 1.65 (95% CI, 1.22–2.25)]. In terms of clinicopathological characteristics, high-grade TB was associated with larger tumor size, higher T and N stage, pleural invasion, vascular invasion, lymphatic invasion, and severe nuclear atypia. Interestingly, smoking showed significant association with high-grade TB, despite the fact that previous studies could not show a significant relationship between them. Furthermore, through our systematic analysis, high-grade TB showed a significant relationship with EMT markers.

Conclusion

Our findings indicate that high-grade TB is associated with a worse prognosis in patients with lung cancer. TB evaluation should be implemented in routine pathological diagnosis, which may guide the patient’s treatment.

Post-neoadjuvant assessment of tumour budding according to ITBCC subgroups delivers stage- and regression-grade independent prognostic information in intestinal-type gastric adenocarcinoma

Tumour budding (TB) has been associated with adverse clinicopathological factors and poor survival in a plethora of therapy‐naïve carcinoma entities including gastric adenocarcinoma (GC). As conventional histopathological grading is usually omitted in the post‐neoadjuvant setting of GC, our study aimed to investigate the prognostic impact of TB in GCs resected after neoadjuvant therapy. We evaluated TB according to the criteria from the International Tumour Budding Consensus Conference (ITBCC) in 167 post‐neoadjuvant resections of intestinal‐type GC and correlated the results with overall survival (OS) and clinicopathological parameters. GCs were categorised into Bd1 (0–4 buds, low TB), Bd2 (5–9 buds, intermediate TB), and Bd3 (≥10 buds, high TB). Carcinomas with intermediate and high TB were significantly enriched in higher ypTNM stages and strongly associated with reduced 5‐year OS in univariable analyses (p < 0.001). In multivariable analyses including sex, age, resection status, UICC stage, and tumour regression grading, TB remained a stage‐independent predictor of survival (p < 0.001, hazard ratio Bd2: 2.60, Bd3: 4.74). The assessment of TB according to the ITBCC criteria provides valuable prognostic information in the post‐neoadjuvant setting of intestinal‐type GC and may be a considerable substitute for the conventional grading system in GCs after neoadjuvant therapy.

Single-Cell Proteomic Analysis Dissects the Complexity of Tumor Microenvironment in Muscle Invasive Bladder Cancer

Simple Summary

The tumor microenvironment (TME) is considered to play a key role in the development of many types of tumors. Muscle invasive bladder cancer (MIBC), which is well known for its heterogeneity, has a highly complex TME. Herein, we integrated mass cytometry and imaging mass cytometry to systematically investigate the complexity of the MIBC TME. Our investigation revealed tumor and immune cells with diverse phenotypes. We identified a specific cancer stem-like cell cluster (ALDH⁺PD-L1⁺ER-β⁻), which is associated with poor prognosis and highlighted the importance of the spatial distribution patterns of MIBC TME components. The present study comprehensively elucidated the complexity of the MIBC TME and provides potentially valuable information for future research.

Abstract

Muscle invasive bladder cancer (MIBC) is a malignancy with considerable heterogeneity. The MIBC tumor microenvironment (TME) is highly complex, comprising diverse phenotypes and spatial architectures. The complexity of the MIBC TME must be characterized to provide potential targets for precision therapy. Herein, an integrated combination of mass cytometry and imaging mass cytometry was used to analyze tumor cells, immune cells, and TME spatial characteristics of 44 MIBC patients. We detected tumor and immune cell clusters with abnormal phenotypes. In particular, we identified a previously overlooked cancer stem-like cell cluster (ALDH⁺PD-L1⁺ER-β⁻) that was strongly associated with poor prognosis. We elucidated the different spatial architectures of immune cells (excluded, infiltrated, and deserted) and tumor-associated collagens (curved, stretched, directionally distributed, and chaotic) in the MIBC TME. The present study is the first to provide in-depth insight into the complexity of the MIBC TME at the single-cell level. Our results will improve the general understanding of the heterogeneous characteristics of MIBC, potentially facilitating patient stratification and personalized therapy.

Impact of molecular surgical margin analysis on the prediction of pancreatic cancer recurrences after pancreaticoduodenectomy

BACKGROUND

Pancreatic cancer is one of the lethal cancers among solid malignancies. Pathological diagnosis of surgical margins is sometimes unreliable due to tissue shrinkage, invisible field cancerization and skipped lesions like tumor budding. As a result, tumor recurrences sometimes occur even from the pathologically negative surgical margins.

METHODS

We applied molecular surgical margin (MSM) analysis by tissue imprinting procedure to improve the detection sensitivity of tiny cancerous cells on the surgical specimen surface after pancreatoduodenectomy. Surgical specimens were collected from 45 pancreatic cancer cases who received subtotal stomach preserving pancreatoduodenectomy at Nagoya University Hospital during 2017-2019. Quantitative methylation-specific PCR (QMSP) of the original methylation marker panel (CD1D, KCNK12, PAX5) were performed and analyzed with postoperative survival outcomes.

RESULTS

Among 45 tumors, 26 cases (58%) were QMSP-positive for CD1D, 25 (56%) for KCNK12 and 27 (60%) for PAX5. Among the 38 tumors in which at least one of the three markers was positive, CD1D-positive cancer cells, KCNK12-positive cancer cells, and PAX5-positive cancer cells were detected at the surgical margin in 8 cases, 7 cases and 10 cases, respectively. Consequently, a total of 17 patients had at least one marker detected at the surgical margin by QMSP, and these patients were defined as MSM-positive. They were associated with significantly poor recurrence-free survival (p = 0.002) and overall survival (p = 0.005) than MSM-negative patients. Multivariable analysis showed that MSM-positive was the only significant independent factor for worse recurrence-free survival (hazard ratio: 3.522, 95% confidence interval: 1.352-9.179, p = 0.010). On the other hand, a significant proportion of MSM-negative cases were found to have received neoadjuvant chemotherapy (p = 0.019).

CONCLUSION

Pancreatic cancer-specific methylation marker panel was established to perform MSM analysis. MSM-positive status might represent microscopically undetectable cancer cells on the surgical margin and might influence the postoperative long-term outcomes.

Prognostic Role of Tumor-Infiltrating Lymphocytes and Tumor Budding in Early Oral Tongue Carcinoma

Objectives/Hypothesis

Occult lymph metastasis is an important prognosticator for the treatment of early oral tongue squamous cell carcinoma (SCC). The objective of this study was to evaluate the prognostic significance of tumor‐infiltrating lymphocytes (TILs) in early oral tongue SCC. The combination of the TIL subtype and intermediate‐ or high‐grade budding scores was investigated as a prognostic marker for occult neck metastases.

Study Design

Retrospective study.

Methods

Specimens from 62 patients with early oral tongue SCC treated with only primary surgery were analyzed by immunohistochemistry for CD4+, CD8+, FoxP3+, and CD45RO+ T cells and CD163+ macrophages. The highest number of each TIL subtype was counted in two areas of parenchyma and stroma in the tumor (Tumor) and peripheral stroma of the invasion margin.

Results

Based on multivariate analysis, a high density of Tumor CD163+ macrophages served as the poorest prognostic factor for regional control (RC) and disease‐free survival (DFS). Patients with both a high density of Tumor CD163+ macrophages and an intermediate‐ or a high‐grade budding score had a poor prognosis for RC according to the log‐rank test.

Conclusions

In summary, each TIL subtype may use different mechanisms during early and advanced stages of oral tongue SCC. A high density of Tumor CD163+ macrophages was determined to be a risk factor for RC and DFS as well as an additional stratification factor for RC in patients with intermediate‐ or high‐grade budding scores. Therefore, identifying TIL subtypes in daily clinical practice can help determine a more successful and individualized therapeutic approach for early oral tongue SCC.

Level of Evidence

Step 4 (Level 4) Laryngoscope, 131:2512–2518, 2021

Pancreatic Cancers with High Grade Tumor Budding Exhibit Hallmarks of Diminished Anti-Tumor Immunity

Simple Summary

Pancreatic cancer, in its most common manifestation pancreatic ductal adenocarcinoma (PDAC), is a uniquely lethal disease with very limited treatment options and few prognostic biomarkers. Tumor budding is a proven independent, adverse prognostic factor in many tumor types including PDAC. Tumor buds can be detected histologically as single cancer cells or clusters of up to four cancer cells at the tumor invasive front. Tumor budding is biologically correlated to the induction of epithelial-mesenchymal transitions (EMT) and disease progression. In this study, we sought to investigate the immunological composition of tumors with high levels of tumor budding. We show that PDAC cases with a high grade of tumor budding display notably diminished anti-tumor immunity. These findings were further validated by gene expression analysis of PDAC cases from The Cancer Genome Atlas (TCGA). Our results provide insight on the immune escape mechanisms of tumor cells undergoing EMT. This offers the potential of designing novel treatments combining immunotherapies with EMT-targeted drugs.

Abstract

Tumor budding is associated with epithelial-mesenchymal transition and diminished survival in a number of cancer types including pancreatic ductal adenocarcinoma (PDAC). In this study, we dissect the immune landscapes of patients with high grade versus low grade tumor budding to determine the features associated with immune escape and disease progression in pancreatic cancer. We performed immunohistochemistry-based quantification of tumor-infiltrating leukocytes and tumor bud assessment in a cohort of n = 111 PDAC patients in a tissue microarray (TMA) format. Patients were divided based on the ITBCC categories of tumor budding as Low Grade (LG: categories 1 and 2) and High Grade (HG: category 3). Tumor budding numbers and tumor budding grade demonstrated a significant association with diminished overall survival (OS). HG cases exhibit notably reduced densities of stromal (S) and intratumoral (IT) T cells. HG cases also display lower M1 macrophages (S) and increased M2 macrophages (IT). These findings were validated using gene expression data from TCGA. A published tumor budding gene signature demonstrated a significant association with diminished survival in PDAC patients in TCGA. Immune-related gene expression revealed an immunosuppressive TME in PDAC cases with high expression of the budding signature. Our findings highlight a number of immune features that permit an improved understanding of disease progression and EMT in pancreatic cancer.

Prognostic value of tumor budding in gallbladder cancer: application of the International Tumor Budding Consensus Conference scoring system

Tumor budding (TB), a histopathological manifestation of epithelial-mesenchymal transition, is an important step in cancer invasion and metastasis development. TB has been considered a strong prognostic indicator in colorectal cancer. The International Tumor Budding Consensus Conference (ITBCC) scoring system is the standardized method used for patient outcome prediction in several human tumors. We investigated the clinicopathological implications and applicability of TB measured using the ITBCC scoring system in gallbladder cancer (GBC). The TB grades assigned to the 78 GBC patients were as follows: Bd1 (low TB), 41 (52.6%) patients; Bd2 (intermediate TB), 22 (28.2%) patients; and Bd3 (high TB), 15 (19.2%) patients. A higher TB grade correlated with a poorer histological differentiation (P < 0.000), higher pT category (P < 0.000), the involvement of surgical resection margin (P = 0.005), presence of nodal metastasis (P < 0.000), lymphatic and venous invasion (P < 0.000), and perineural invasion (P = 0.004). Univariate Cox regression analysis revealed that a poor histological grade, high pT category, lymphatic invasion, perineural invasion, and intermediate to high TB grades were associated with worse 5-year overall survival and disease-free survival. TB was not significantly associated with death or recurrence risk in multivariate Cox analysis. The interobserver agreement of TB grading was substantial. This study is the first to apply the ITBCC scoring system and suggest the prognostic value of TB in GBC.

Prognostic impact of tumor budding in endometrial carcinoma within distinct molecular subgroups

Tumor budding is a robust prognostic parameter in several tumor entities but is rarely investigated in endometrial carcinoma. We applied the recently standardized counting method from the International Tumor Budding Consensus Conference for colorectal cancer (ITBCC) on a cohort of 255 endometrial carcinomas with known molecular profiles according to The Cancer Genome Atlas (TCGA) subgroups. Our investigation aims to clarify the potential prognostic role of tumor budding in endometrial carcinoma in contrast to other known prognostic factors, including molecular factors. In addition, the microcystic elongated and fragmented (MELF) pattern and tumor budding were compared with respect to their potential as markers for epithelial-mesenchymal transition (EMT). Tumor budding was found in n = 67 (26.3%) tumors, with a very low mean of 0.7 buds per ×20 HE field. Tumor budding was significantly associated with depth of invasion, nodal status, lymphatic invasion (each p < 0.001), grading (p = 0.004), and vascular invasion (p = 0.01). Tumor budding showed moderate inter-observer-variability with prognostic stratification irrespective of the observer (κ-value = 0.448). In multivariate analysis, tumor budding served as a significant independent prognosticator for worse outcomes in overall and recurrence-free survival (HR 2.376 and 2.736, p < 0.001), but not when the TCGA subgroups entered into the analysis. In consequence, dependency had to be clarified in the subgroup analysis for Polymerase E mutated (POLEmut), mismatch repair deficient (MMRdef), nonspecific mutation profile (NSMP), and P53 aberrant (P53abn) endometrial carcinomas. A particular impact was identified in the intermediate prognostic groups of NSMP and MMRdef carcinomas. Tumor budding outperformed the MELF pattern in single and combined prognostic information. In conclusion, the presence of tumor budding alone is a promising, robust, and easy-to-apply prognostic parameter in endometrial carcinoma. In a morpho-molecular approach, it exerts its prognostic potential in the most clinically relevant subgroups of endometrial carcinoma and serves as a good biomarker for EMT.

Reproducibility of tumor budding assessment in pancreatic cancer based on a multicenter interobserver study

Tumor budding has been reported to be an independent prognostic factor in pancreatic ductal adenocarcinoma (PDAC). Its use in daily diagnostics would improve the prognostic stratification of patients. We performed a multicenter interobserver study to test various budding assessment methods for their reproducibility. Two serial sections of 50 resected, treatment-naïve PDACs were stained for Hematoxylin and Eosin (H&E) and pancytokeratin. Tumor budding was scored by independent observers at five participating centers in Switzerland, Germany, and Canada. Pathologists assessed tumor budding on a digital platform comparing H&E with pancytokeratin staining in 10 high-power fields (10HPF) and one HPF hotspot (1HPF). Additionally, tumor budding was assessed in one H&E hotspot at × 20 magnification, as suggested by the International Tumor Budding Consensus Conference (ITBCC). Correlation coefficients for bud counts between centers ranged from r = 0.58648 to r = 0.78641 for H&E and from r = 0.69288 to r = 0.81764 for pancytokeratin. The highest interobserver agreement across all centers was observed for pancytokeratin 10HPFs (ICC = 0.6). ICC values were 0.49, 0.48, 0.41, and 0.4 for H&E in 1HPF hotspot, H&E in 10HPFs, pancytokeratin in 1HPF, and H&E in one hotspot at ×20, respectively (ITBCC method). This interobserver study reveals a range between moderately poor to moderate agreement levels between pathologists for the different tumor budding assessment methods in PDAC. Acceptable levels of agreement were reached with the pancytokeratin 10HPF method, which can thus be recommended for the assessment of tumor budding in PDAC resection specimens. To improve the levels of interobserver agreement, the implementation of machine learning applications should be considered.

FAK activity in cancer-associated fibroblasts is a prognostic marker and a druggable key metastatic player in pancreatic cancer

Cancer-associated fibroblasts (CAFs) are considered the most abundant type of stromal cells in pancreatic ductal adenocarcinoma (PDAC), playing a critical role in tumour progression and chemoresistance; however, a druggable target on CAFs has not yet been identified. Here we report that focal adhesion kinase (FAK) activity (evaluated based on 397 tyrosine phosphorylation level) in CAFs is highly increased compared to its activity in fibroblasts from healthy pancreas. Fibroblastic FAK activity is an independent prognostic marker for disease-free and overall survival of PDAC patients (cohort of 120 PDAC samples). Genetic inactivation of FAK within fibroblasts (FAK kinase-dead, KD) reduces fibrosis and immunosuppressive cell number within primary tumours and dramatically decreases tumour spread. FAK pharmacologic or genetic inactivation reduces fibroblast migration/invasion, decreases extracellular matrix (ECM) expression and deposition by CAFs, modifies ECM track generation and negatively impacts M2 macrophage polarization and migration. Thus, FAK activity within CAFs appears as an independent PDAC prognostic marker and a druggable driver of tumour cell invasion.

Hypoxia, partial EMT and collective migration: Emerging culprits in metastasis

Epithelial-mesenchymal transition (EMT) is a cellular biological process involved in migration of primary cancer cells to secondary sites facilitating metastasis. Besides, EMT also confers properties such as stemness, drug resistance and immune evasion which can aid a successful colonization at the distant site. EMT is not a binary process; recent evidence suggests that cells in partial EMT or hybrid E/M phenotype(s) can have enhanced stemness and drug resistance as compared to those undergoing a complete EMT. Moreover, partial EMT enables collective migration of cells as clusters of circulating tumor cells or emboli, further endorsing that cells in hybrid E/M phenotypes may be the 'fittest' for metastasis. Here, we review mechanisms and implications of hybrid E/M phenotypes, including their reported association with hypoxia. Hypoxia-driven activation of HIF-1α can drive EMT. In addition, cyclic hypoxia, as compared to acute or chronic hypoxia, shows the highest levels of active HIF-1α and can augment cancer aggressiveness to a greater extent, including enriching for a partial EMT phenotype. We also discuss how metastasis is influenced by hypoxia, partial EMT and collective cell migration, and call for a better understanding of interconnections among these mechanisms. We discuss the known regulators of hypoxia, hybrid EMT and collective cell migration and highlight the gaps which needs to be filled for connecting these three axes which will increase our understanding of dynamics of metastasis and help control it more effectively.

Malignant epithelial/exocrine tumors of the pancreas

Pancreatic malignant exocrine tumors represent the most important cause of cancer-related death for pancreatic neoplasms. The most common tumor type in this category is represented by pancreatic ductal adenocarcinoma (PDAC), an ill defined, stroma-rich, scirrhous neoplasm with glandular differentiation. Here we present the relevant characteristics of the most important PDAC variants, namely adenosquamous carcinoma, colloid carcinoma, undifferentiated carcinoma, undifferentiated carcinoma with osteoclast-like giant cells, signet ring carcinoma, medullary carcinoma and hepatoid carcinoma. The other categories of malignant exocrine tumors, characterized by fleshy, stroma-poor, circumscribed neoplasms, include acinar cell carcinoma (pure and mixed), pancreatoblastoma, and solid pseudopapillary neoplasms. The most important macroscopic, histologic, immunohistochemical and molecular hallmarks of all these tumors, highlighting their key diagnostic/pathological features are presented. Lastly, standardized indications regarding gross sampling and how to compile a formal pathology report for pancreatic malignant exocrine tumors will be provided.

Tumour budding and its clinical implications in gastrointestinal cancers

Tumour budding in colorectal cancer has become an important prognostic factor. Represented by single cells or small tumour cell clusters at the invasion front of the tumour mass, these tumour buds seem to reflect cells in a ‘hybrid’ state of epithelial–mesenchymal transition, and evidence indicates that the presence of these entities is associated with lymph node metastasis, local recurrence and distant metastatic disease. The International Tumour Budding Consensus Conference (ITBCC) has highlighted a scoring system for the reporting of tumour budding in colorectal cancer, as well as different clinical scenarios that could affect patient management. Other organs are not spared: tumour budding has been described in numerous gastrointestinal and non-gastrointestinal cancers. Here, we give an update on ITBCC validation studies in the context of colorectal cancer and the clinical implications of tumour budding throughout the upper gastrointestinal and pancreatico-biliary tract.

Validation of the International Tumor Budding Consensus Conference (ITBCC) 2016 recommendation in squamous cell carcinoma of the lung-a single-center analysis of 354 cases

There are no universally accepted grading systems in pulmonary squamous cell carcinoma (pSQCC). Recently, tumor budding, cell nest size, and spread through airspaces (STAS) have been proposed as grading scheme candidates. Tumor budding is a well-established independent prognostic factor in colorectal cancer. The International Tumor Budding Consensus Conference (ITBCC) provided consensus on scoring in 2016, albeit for colorectal cancers. Here, we aimed to validate the ITBCC method in pSQCC and evaluate additional proposed grading parameters. We analyzed a fully clinico-pathologically annotated Western single-center cohort of 354 consecutive primary resected pSQCC (resected 2000-2013). Patients with SQCC of other organs were excluded to reliably exclude lung metastases. We assessed conventional grading, keratinization, STAS, and tumor budding according to ITBCC recommendations, and correlated them with clinico-pathological parameters and survival. Tumor budding was low (0-4 buds/0.785 mm²) in 41%, intermediate (5-9 buds/0.785 mm²) in 30%, and high (≥10 buds/0.785 mm²) in 29% of cases (mean bud count = 7.45 (H&E), min = 0, max = 84). Cell nests of 1, 2-4, 5-15, >15 cells were present in 68%, 20%, 5%, 7%, respectively. We detected STAS in 33% of cases, desmoplasia in 68%. Tumor budding assessed as continuous and categorized variables was highly concordant between hematoxylin and eosin (H&E) and pancytokeratin (AE1/AE3) stained slides (P < 0.001) and significantly associated with tumor size, UICC/AJCC pT, pN, stage (all P < 0.001) and presence of mediastinal lymph node metastases (H&E: P = 0.028). Tumor budding was a significant prognostic parameter for overall, disease-specific, and progression-free survival (PFS) (all P < 0.001). ITBCC tumor budding categories were independent prognostic factors for overall survival (HR = 1.581; 95% CI 1.186-2.108; P = 0.002), disease-specific survival (HR = 1.710; 95% CI 1.111-2.632; P = 0.015), and PFS (HR = 1.457; 95% CI 1.123-1.890; P = 0.005). STAS or conventional tumor grade had no prognostic value. In conclusion, we confirm tumor budding as an independent prognostic marker in pSQCC and validate the ITBCC 2016 scoring recommendations in pSQCC.

Tumor budding as a prognostic factor in pancreatic ductal adenocarcinoma

In this retrospective study, we analyzed the association between tumor budding and perineural invasion as well as their prognostic role in pancreatic ductal adenocarcinoma. A total of N = 119 patients resected for pancreatic ductal carcinoma from 1996 to 2015 were included. Clinical and standard histopathological parameters were retrieved from the patient's records. One representative hematoxylin and eosin section from the tumor region was examined for perineural invasion and tumor budding using light microscopy. Tumor budding was assessed independently using two different methods: in the first approach, the number of buds was counted over three fields of 0.237 mm2 at 40-fold magnification; in the second approach, tumor budding was quantified according to the recommendation of the International Tumor Budding Consensus Conference (ITBCC) over a field of 0.785 mm2 at 20-fold magnification. Linear and logistic regression was applied to delineate association between perineural invasion, tumor budding, and other parameters; Kaplan-Meier and Cox regression were used in the survival analysis. Regardless of the quantification approach, high tumor budding was a significant negative prognostic factor in the univariable Cox regression (> 5 buds/0.237 mm2, hazard ratio (HR) 1.66, 95% confidence interval (CI) 1.06-2.61, p = 0.027; ≥ 10 buds/0.785 mm2, HR 1.68, 95% CI 1.07-2.64, p = 0.024). In the multivariable model adjusting for stage and standard histopathological parameters, lymph vessel invasion (HR = 2.43, 95% CI 1.47-4.03, p = 0.001) and tumor budding > 5 buds/0.237 mm2 (HR = 1.70, 95% CI 1.07-2.7, p = 0.026) were independent negative prognostic factors, while adjuvant therapy was a positive prognostic factor (HR = 0.54, 95% CI 0.33-0.86, p = 0.009). No significant prognostic value could be delineated for perineural invasion. In conclusion, tumor budding is an independent negative prognostic factor in pancreatic ductal adenocarcinoma associated with lymph node metastasis. The prognostic role of perineural invasion remains uncertain.

Separation of Low- Versus High-grade Crohn's Disease-associated Small Bowel Carcinomas is Improved by Invasive Front Prognostic Marker Analysis

BACKGROUND AND AIMS

Crohn's disease-associated small bowel carcinoma is a rare event, usually reported to have a severe prognosis. However, in previous investigations we have found a minority of cases displaying a relatively favourable behaviour, thus outlining the need to improve the histopathological prediction of Crohn's disease-associated small bowel carcinoma prognosis.

METHODS

As in recent studies on colorectal cancer, a substantial improvement in prognostic evaluations has been provided by the histological analysis of the tumour invasive front; we therefore systematically analysed the tumour budding and poorly differentiated clusters in the invasive front of 47 Crohn's disease-associated small bowel carcinomas collected through the Small Bowel Cancer Italian Consortium.

RESULTS

Both tumour budding and poorly differentiated cluster analyses proved highly effective in prognostic evaluation of Crohn's disease-associated small bowel carcinomas. In addition, they retained prognostic value when combined with two other parameters, i.e. glandular histology and stage I/II, both known to predict a relatively favourable small bowel carcinoma behaviour. In particular, association of tumour budding and poorly differentiated clusters in a combined invasive front score allowed identification of a minor subset of cancers [12/47, 25%] characterised by combined invasive front low grade coupled with a glandular histology and a low stage [I or II] and showing no cancer-related death during a median follow-up of 73.5 months.

CONCLUSIONS

The improved distinction of lower- from higher-grade Crohn's disease-associated small bowel carcinomas provided by invasive front analysis should be of potential help in choosing appropriate therapy for these rare and frequently ominous neoplasms.

A Proposal to Revise the Histopathologic Grading System of Early Oral Tongue Cancer Incorporating Tumor Budding

The World Health Organization (WHO) grading system has a low prognostic value for early-stage oral tongue squamous cell carcinoma; greater prognostic power has been shown with tumor budding analysis. In this study, we combined tumor budding analysis with histopathologic grading according to WHO 2017. In our proposal, a revised grade I tumor is defined as a "well differentiated cohesive tumor"; revised grade II as a "moderately differentiated and/or slightly dissociated tumor"; and revised grade III as a "poorly differentiated and/or dissociated tumor." We evaluated the prognostic value of this proposed grading system in a multicenter cohort of 311 cases of early oral tongue squamous cell carcinoma. The proposed grading system showed significant prognostic value in multivariable analysis for disease-specific survival with a hazard ratio of 3.86 and a 95% confidence interval of 1.36-10.9 (P=0.001). For disease-free survival, the proposed grading system showed good predictive power in multivariable analysis (hazard ratio, 2.07; 95% confidence interval, 1.00-4.27; P=0.009). The conventional WHO grading system showed a low prognostic value for disease-specific survival and disease-free survival (P>0.05). In conclusion, the prognostic power of the WHO histopathologic grading improved significantly with incorporation of tumor budding. Our proposed grading system can be easily included in pathology reports.

A classification based on tumor budding and immune score for patients with hepatocellular carcinoma

Background: The role of immune profiling and tumor budding in hepatocellular carcinoma (HCC) remains largely unknown. This study evaluated the association between tumor budding and lymphocytic infiltration in HCC. Meanwhile, HCC patients were stratified based on tumor budding grade and immune score.

Patients and methods: A total of 423 HCC patients were divided into training (n = 212) and validation (n = 211) cohort. Tumor slides from resected HCC samples were used for tumor budding assessment. A prognosis-relevant immune score was developed based on five types of immune cells out of eleven immune markers. A classification based on tumor budding grade and immune type was established (IS-TB type). To explore the association of IS-TB type and molecular alterations of HCC, 100 HCC samples and adjacent non-tumor tissues from 100 patients were investigated by whole-exome sequencing.

Results: Tumor budding was an independent adverse prognostic factor for OS and DFS in both of the training and validation cohorts (all P values <.05). The rate of high-grade tumor budding was significantly higher in HCC with immature stroma (P < .001), strong α-SMA expression (P = .005), non-steatotic tumors and non-fibrolamellar-HCC (P < .001). Additionally, tumor budding was related to both anti- and pro-tumor immune responses. Patients were classified into immune type A and immune type B according to the immune score. Based on tumor budding grade and immunotype, patients were classified into four subgroups: IS_A-TB_high (type I), IS_B-TB_high (type II), IS_A-TB_low (type III) and IS_B-TB_low (type IV). Patients with type III tumor had the best OS and DFS, whereas OS and DFS were the worst for cases with type II tumor. TP53 mutation was more frequent in IS-TB type I (IS_ATB_high) patients, while IS-TB type IV (IS_BTB_low) harbored high number of CTNNB1 mutation.

Conclusion: Tumor-immune cell interactions in HCC is heterogeneous. HCC classification based on tumor budding and immune score correlates with patient survival and molecular alterations. The defined subtypes may have significance for utilizing individualized treatment in patients with HCC.

Clinical Scenarios Emerging from Combined Immunophenotypic, Molecular and Morphologic Analysis of Pancreatic Cancer: The Good, the Bad and the Ugly Scenario

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with increasing incidence and dismal prognosis. The composition of the immune cell infiltrates in the tumor microenvironment (TME) and the dynamic interplay between cancer- and immune cells can influence and/or be influenced by tumor-intrinsic characteristics like molecular profiles and tumor cell morphology. The combined analyses of pancreatic cancer by using morphologic, genetic, and immunologic features help us understand the significant heterogeneity of the TME and recognize the different mechanisms of immune evasion. Moreover, this information may lead to the identification of novel biomarkers for more precise patient stratification and therapy guidance.

Does evaluation of tumour budding in diagnostic biopsies have a clinical relevance? A systematic review

Tumour budding has emerged as a promising prognostic marker in many cancers. We systematically reviewed all studies that evaluated tumour budding in diagnostic biopsies. We conducted a systematic review of PubMed, MEDLINE, Scopus, Web of Science and Cochrane library for all articles that have assessed tumour budding in diagnostic (i.e. pretreatment or pre-operative) biopsies of any tumour type. Two independent researchers screened the retrieved studies, removed duplicates, excluded irrelevant studies and extracted data from the eligible studies. A total of 13 reports comprising 11 cohorts were found to have studied tumour budding in diagnostic biopsies. All these reports showed that evaluation of tumour budding in diagnostic biopsies was easily applicable. A strong association was observed between tumour budding score in diagnostic biopsies and corresponding surgical samples. Evaluation of tumour budding in diagnostic biopsies had a significant prognostic value for lymph node metastasis and patient survival. In all studies, tumour budding was a valuable marker of tumour aggressiveness and can be evaluated in technically satisfactory diagnostic biopsies. Thus, the assessment of tumour budding seems to identify the behaviour of cancer, and therefore to facilitate treatment planning.

Prognostic Role of High-Grade Tumor Budding in Pancreatic Ductal Adenocarcinoma: A Systematic Review and Meta-Analysis with a Focus on Epithelial to Mesenchymal Transition

This study aims at clarifying the prognostic role of high-grade tumor budding (TB) in pancreatic ductal adenocarcinoma (PDAC) with the first systematic review and meta-analysis on this topic. Furthermore, we analyzed with a systematic review the relationship between TB and a recently suggested TB-associated mechanism: the epithelial to mesenchymal transition (EMT). Analyzing a total of 613 patients, 251 of them (40.9%) with high grade-TB, we found an increased risk of all-cause mortality (RR, 1.46; 95% CI, 1.13⁻1.88, p = 0.004; HR, 2.65; 95% CI, 1.79⁻3.91; p < 0.0001) and of recurrence (RR, 1.61; 95% CI, 1.05⁻2.47, p = 0.03) for PDAC patients with high-grade TB. Moreover, we found that EMT is a central process in determining the presence of TB in PDAC. Thanks to this meta-analysis, we demonstrate the potential clinical significance of high-grade TB for prognostic stratification of PDAC. TB also shows a clear association with the process of EMT. Based on the results of the present study, TB should be conveyed in pathology reports and taken into account by future oncologic staging systems.